Hydrogen and the Light-Induced Bias Instability Mechanism in Amorphous Oxide Semiconductors.
Sci Rep 2017;
7:16858. [PMID:
29203820 PMCID:
PMC5714999 DOI:
10.1038/s41598-017-17290-5]
[Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/22/2017] [Indexed: 11/08/2022] Open
Abstract
Hydrogen is known to be present as an impurity in amorphous oxide semiconductors at the 0.1% level. Using amorphous ZnO as a simplified model system, we show that the hydrogens pair up at oxygen vacancies in the amorphous network, where they form metal-H-metal bridge bonds. These bonds are shown to create filled defect gap states lying just above the valence band edge and they are shown to give a consistent mechanism to explain the negative bias illumination stress instability found in oxide semiconductors like In-Ga-Zn-O (IGZO).
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